Is it possible to burn an iso image to a DVD using cmd in Windows 7 or 8?

Yes it is possible to burn iso files from the windows command line, however only in Windows 7 and above.

How to Burn an Image from the Command Line in Windows

ISO or IMG image files can be burned in both Windows 7 or 8 from the command line quite easily. First, open the Command Prompt and then type isoburn to get the following guick syntax guide. As has been noted in the discussion below, you don't need to reference.exe since it lives in the system32 folder.

Start isoburn.exe using the following command and parameters:

Syntax:

isoburn.exe /q [the CD/DVD writing drive] 

Example:

isoburn.exe /q D: C:\Users\JDoe\Desktop\image.iso

After a few moments, you'll see:

While yes, the process can be fired up from the command line, this window may still need to be closed by hand.

See Also:

http://www.tutorialized.com/tutorial/The-Complete-Guide-to-Burning-Disk-Images-(ISO-&-IMG)-In-Windows-7/71219

isoburn /q <drive letter>: <disc image>

that should work.